In Japanese Patent Publication Kokai No. Hei 5-289672, an apparatus is disclosed which recognizes chords of a music piece to make data representing the music piece as variations in the chords, i.e., as chord progression.
In accordance with music information previously notated (note information of sheet music), the apparatus disclosed in the publication determines a chord based on note components appearing at each beat or those that are obtained by eliminating notes indicative of non-harmonic sound from the note components, thereby making data representative of the chord progression of the music piece.
However, in the conventional music date making apparatus, music pieces with known beats of which chords can be analyzed are limited, and data indicative of chord progression from music sound with unknown beats can not be made.
Additionally, it is impossible for the conventional apparatus to analyze chords of a music piece from an audio signal indicative of the sound of the music piece in order to make data as chord progression.